Bone mineralization is one of those lack-of-gravity problems. For each month in space, Logan says the human body loses 1 percent of its bone mass. And, once back on Earth, the bones don’t grow back.
“I’m not trying to throw cold water on the idea of going to Mars. I want to make sure we can survive if we do go,” Logan said.
He says, if putting humans on Mars is truly a near-term goal, it means studies today must focus on Martian gravity, or 0.38 Gs.
“If we study the effect of 0.38 on the body around the clock, and it doesn’t work, you can cross off Mars as a human settlement site until we do sort out the medical diagnosis,” Logan said.
After medically serving 25 space shuttle missions, Logan stated current measures are stop-gaps that do little to actually counteract the effects of weightlessness on the body.
For “each deleterious effect,” Logan says there’s a new mechanical or pharmaceutical countermeasure that only “retards the deconditioning. They don’t neutralize it and they don’t reduce it,” Logan said.
“We need to start sending more people into space if we’re actually going to get somewhere, with even problems we know like the gravity prescription,” he added.
The scientist also said that it is critical to use the words “outpost” and “settlement” distinctly when talking about space exploration.
“Let’s stop playing fast and loose with this idea that the ISS [International Space Station] is our first settlement in space. We have a permanent presence, but with rotating crews,” Logan added. “Settlement is men, women, children, over multiple generations.”